diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2021-07-28 18:24:02 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-07-29 12:18:12 +0100 |
| commit | 9efb4b5baf6ce851b247288992b0632cb4d31c17 (patch) | |
| tree | aab2e005f5c5566917a80cae3349dceae7d26572 /net/core/dev.c | |
| parent | b0999f385ac30cb17880ae1c1512491fbf0c9542 (diff) | |
| download | linux-9efb4b5baf6ce851b247288992b0632cb4d31c17.tar.bz2 | |
net: optimize GRO for the common case.
After the previous patches, at GRO time, skb->slow_gro is
usually 0, unless the packets comes from some H/W offload
slowpath or tunnel.
We can optimize the GRO code assuming !skb->slow_gro is likely.
This remove multiple conditionals in the most common path, at the
price of an additional one when we hit the above "slow-paths".
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index fb5d12a3d52d..19565f7497ee 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6014,7 +6014,6 @@ static void gro_list_prepare(const struct list_head *head, diffs |= skb_vlan_tag_present(p) ^ skb_vlan_tag_present(skb); if (skb_vlan_tag_present(p)) diffs |= skb_vlan_tag_get(p) ^ skb_vlan_tag_get(skb); - diffs |= skb_metadata_dst_cmp(p, skb); diffs |= skb_metadata_differs(p, skb); if (maclen == ETH_HLEN) diffs |= compare_ether_header(skb_mac_header(p), @@ -6024,17 +6023,29 @@ static void gro_list_prepare(const struct list_head *head, skb_mac_header(skb), maclen); - diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb); + /* in most common scenarions _state is 0 + * otherwise we are already on some slower paths + * either skip all the infrequent tests altogether or + * avoid trying too hard to skip each of them individually + */ + if (!diffs && unlikely(skb->slow_gro | p->slow_gro)) { +#if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT) + struct tc_skb_ext *skb_ext; + struct tc_skb_ext *p_ext; +#endif + + diffs |= skb_metadata_dst_cmp(p, skb); + diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb); + #if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT) - if (!diffs) { - struct tc_skb_ext *skb_ext = skb_ext_find(skb, TC_SKB_EXT); - struct tc_skb_ext *p_ext = skb_ext_find(p, TC_SKB_EXT); + skb_ext = skb_ext_find(skb, TC_SKB_EXT); + p_ext = skb_ext_find(p, TC_SKB_EXT); diffs |= (!!p_ext) ^ (!!skb_ext); if (!diffs && unlikely(skb_ext)) diffs |= p_ext->chain ^ skb_ext->chain; - } #endif + } NAPI_GRO_CB(p)->same_flow = !diffs; } @@ -6299,8 +6310,11 @@ static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb) skb->encapsulation = 0; skb_shinfo(skb)->gso_type = 0; skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)); - skb_ext_reset(skb); - nf_reset_ct(skb); + if (unlikely(skb->slow_gro)) { + skb_ext_reset(skb); + nf_reset_ct(skb); + skb->slow_gro = 0; + } napi->skb = skb; } |